Electrical fuse device



Aug. 14, 1945.-

c L. SCHU CK ELECTRICAL FUSE DEVICE Filed June 7, 1943 Inventor. Carl L. Schuck,

H55 Attorney.

m m z A E L w m P .w m A m a \l// s w Patented Aug. 14, 1945 ELECTRICAL FUSE DEVICE Carl L. Schuck, Philadelphia, Pa., assignor to General Electric Company, a corporation of New York Application June '7, 1943, Serial No. 489,895

3 Claims.

My invention relates to electrical fuse devices and more particularly to a new and improved mounting and buffer arrangement for fuses.

As a general rule fuses such as of the current limiting type disclosed and claimed in Rankin Patent 2,188,816, assigned to the same assignee as the present application, are usually mounted in a vertical manner as disclosed in my prior Patent 2,259,142. In such cases the fuse is replaced by bodily removing the burned out fuse from the supporting structure and replacing it wtih a new fuse. Occasionally it is desired for various reasons to mount such fuses in a horizontal manner with the supporting structure for the fuse above the fuse. My invention is particularly concerned with the last-mentioned arrangement generally referred to as inverted mounting arrangements for fuses.

It is an object of my invention to provide an inverted mounting arrangement for fuses designed so as to provide positive assurance against the fuse unit falling out of the fuse clips while in service.

It is another object of my invention to provide a new and improved buffer arrangement for a fuse.

Further objects and advantages of my inven-' tion will become apparent as the following description proceeds and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention reference may be had to the accompanying drawing, in which Fig. 1 is a view, partly in section, of the fuse and supporting means therefor embodying my invention; Fig. 2 is a view similar to Fig. 1 showing the fuse released from the contact clips and pushed against the buffer; Fig. 3 is an enlarged end view partially in section to illustrate the path of the fuse in inserting and removing the same, and Fig. 4 is a perspective view of a portion of the mounting arrangement to more clearly illustrate the inverted mounting construction and buffer arrangement.

As will be evident from the ensuing description, various features of the present invention are subject to modification and are suitable for employment in other forms of electrical circuit interrupting devices. Hence the embodiment shown in the drawing is for the purpose of illustration only. -In this embodiment the fuse support includes two insulators l and H disposed in spaced relationship and bolted or otherwise secured at one end to a suitable horizontally mounted base l2. On the outer end of each insulator there is supported a terminal and contact clip assembly generally indicated at l3 having a projecting portion M to which electric line conductors, or leads, may be secured by a clamping device such as [5.

In order to provide positive assurance that the fuse unit generally indicated at [6 in Fig. 1 cannot fall out of the fuse clips I! while in service, I provide for each insulator I0 and H, a fuse clip supporting member ill of generally U-shaped construction as best shown in Figs. 3 and 4, which has one end of the U suitably bolted to the insulator In or H as by bolts 22 while the fuse clip I! is suitably fastened to the other end with the open end of the clip extending upwardly so that the fuse unit l6 can only be removed by upward movement thereof until it is free of the fuse clip H.

A fuse unit or fuse device such as indicated at l6, preferably of the form shown in the above mentioned Rankin patent, may be of considerable size and weight, particularly when designed for high current interrupting ratings so that the inverted mounting described above insures that the fuse device will not fall out in use. Such fuse devices as disclosed in the Rankin patent include a fusible element and an insulating support therefor embedded in a body of sand or granular quartz, which is contained within a tubular glassv casing the opposite ends of which are closed by metallic caps or ferrules such as are indicated at I9. The ferrules l9 are adapted to be electrically engaged by the terminal clip I! forming part of the terminal and contact clip assembly l3.

Since the tubular casing of the fuse I6 is frangible care must be taken in inserting and removing the fuse device to prevent breakage thereof. Generally a fuse tongs, such as is indicated at 20, is used for handling the fuse device IG, which tongs tightly grip the fuse casing between suitable jaws.

With the arrangement described thus far it will be obvious that without retardation after removal of the fuse I6 from the contact clips I1, breakage of the fuse casing might result by striking the fuse device 16 against the terminals 14 and mounting bolts 22. This happens because the contact clips IT, in order to insure good current carrying contact with the ferrules l9, firmly grip the ends of the ferrules so that a considerable force must be applied to fuse tongs 20 in order to move the fuse device l6 out of engagement with clips [1, and consequently, as soon as the fuse [6 is released from the clips, this force will cause the ferrules I9 to strike the terminals I4 and mounting bolts 22, the shock causing breakage of the frangible casing. Accordingly, to protect the fuse device [6 I have provided a flexible buffer strip 2| associated with each terminal and contact clip assembly l3. This flexible buffer strip 2| is suitably fastened to one end of the U-shaped support l8 as indicated by bolts 22 while the other end thereof is fastened to the center of the U as indicated at 23. A suitable helical spring 24 is provided between buffer strip 2| and insulator ID, the spring 24 being supported in aligned openings 25 and 26. inv

U-shaped member I8 and terminal I 4, respectively. The helical spring 24 biasing the buffer strip 2|, is held in place in the aligned openings 25 and 26 by stakes 21 which may bemade by a center punch or the like.

As best shown in Fig. 3, when the fuse device I6 is removed from the contact clips l 'lby pushing upward on fuse tongs 20' breakage due toshock is prevented since the fuse device I6 stops gradually against the buffer comprising springs biased buffer strips 2t. The path of the fuse while being inserted or removed: isshown by the dotted circles in Fig. Bindicating successive positions of the fuse device It From the above description it will be obvious that I have provided an inverted mounting for a fuse device which provides positive assurance against the fuse unit or fuse. device falling out of the fuse clips while in service. Furthermore, the new and improved buffer arrangement prevents breakage particularly in connection with:

removal of the fuse units or replacement of the same.

While I have described what I at present consider the preferred embodiment of my invention it will be obvious to those skilled in the artthat various changes and modifications maybe made without departing from my invention, and I.

therefore aim in the appended claims to; cover such changes and modifications asfall within the true spirit and scope of. my invention;

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In an electric fuse arrangement, a supporting structure having spaced terminals, a fuse device connected between said terminals comprising a frangible casing having end ferrules electrically engaging said terminals, said supporting, structure being arranged. so that bodily removal of said fuse device is accomplished by first moving said device toward said supporting structure to disengage said ferrules from said terminals, and means on said supporting struc ture for cushioning each end of said fuse device to prevent breakage of said frangible casing upon movement of said fuse device toward said supporting structure.

2. In an electric fuse arrangement, a supporting structure having spaced terminals, a fuse device connected between said terminals comprising a frangible casing having end ferrules electrically engaging said terminals, said supporting structure being arranged so that bodily removal of saidfusedevioe is accomplished by first moving said device toward said supporting structure to disengage said ferrules from said terminals, and means on said supporting structure for cushioning said fuse device to prevent breakage of said frangible casing upon movement of said fuse device toward said supporting structure.

3 In an electric fuse arrangement, a supporting structure having spaced terminals, a fuse device connected between said terminals comprising a frangible casing having end ferrules electrically engaging said terminals, said supporting structure being arranged so that bodily removal of said fuse device is accomplished by first moving said device toward said supporting structure to disengage said ferrules from said terminals, and means on said supporting structure comprising a spring biased buffer strip for cushioning said fuse device to prevent breakage of said frangible casing upon movement of said fuse device toward said supporting structure.

CARL L. SCHUCK 

